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looking for other ideas on this problem. Removing an old service with 3-200 amp main panels with existing conduit to them (approx 4-8 per panel). We have always either made them fit back in existing holes or made new ones with basically an x/y axis and a ruler. One panel in particular has 3x1/2EMT, 2-3/4, 2x1",1x1.25 conduits with existing feeders which need to reconnect. Gonna swap guts with a new non punched enclosure. Could do the old x/y thing again but it is time consuming and we are on a 4 hour disconnect/reconnect schedule (running facility) is there some sort of clamp/laser beam invention out there that would give us spot on center of new holes to punch? In not, there is an idea. I was just going to make up some sort of 3 prong clamp and attach a laser on center of bottom to give us an accurate center punch area or something to that effect. Most likely it will involve duct tape. I would rather buy something from greenlee or whoever if they have it.

Any tips out there
 

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Are you measuring the existing conduits, or are you measuring the holes in the old panel? The latter is far faster and more accurate.

Also, suck it up and get a Greenlee C-frame punch.


Model 1731 does ½, ¾ and 1" KOs, 1732 goes to 4"​
 

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Man they dont give that thing away do they???

No, but they sure are damn nice to have. And they truly do save labor.

You only need to mark the center of the hole with the 1731. No crosshairs to line up with quarter marks on the dies. It has a spring-loaded pin that you just put on the center mark, and punch it. No holes to predrill, either.
 

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I've never even heard of the C-Frame punch.
Until you use one, you really don't know how much faster it is over predrilling a hole, then using a standard KO punch set and having to unthread the punch off the draw stud for every KO.




I won't tell you I bought mine nearly new for $138......
 

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Whenever I have had to do that, the old panel is junk. So I just cut the section of panel off I need, top, bottom, back, etc. And use that as a template.
 

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So I just cut the section of panel off I need, top, bottom, back, etc. And use that as a template.
Thats what I do, cut the old top piece off, mount the box, then put the old top piece on and trace the holes with a sharpie.

Or if I'm extending a pipe to a new enclosure I hook this on:

http://www.mygreenlee.com/Products/...=showGreenleeProductTemplate&upc_number=03582

Although I don't think its pin point accurate and you still need to compensate for the true centre. Not to mention its not as nice fastening to pipe with box connectors on it, its only meant for clean cut pipe.
 

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I just cut the section of panel off I need, top, bottom, back, etc. And use that as a template.
I just pull the old panel and make a cardboard template.

I use carbide hole saws up to 1.5" and a punch for larger ones.
 

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Is there any reason you can't pre-measure and pre-punch the new tub?
 

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Your saying you cant pre-measure make a template out of cardboard...then use step bit or greenlee hydraulic punch ?? c-punch looks pricey just for a one time thing unless you can find them for a daily rental. Been a comm/indust electrician for 11+ years, haven't used a cpunch yet.
 

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LOL at that green-lee C-Punch, I would try a finger nail file, before I pay $3000 for a punch. BTW harbor freight makes a ko punch set for $100 works great. Oh yeah sweat deal $138.
 

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LOL at that green-lee C-Punch, I would try a finger nail file, before I pay $3000 for a punch. BTW harbor freight makes a ko punch set for $100 works great. Oh yeah sweat deal $138.
You're comparing apples to oranges. Would you just as readily say, "What do I need a trencher for? I already have a shovel!" Yes, you still get the same hole in the panel, but the c-punch will save you 90% of the labor.

The 1731 does not need crosshairs to center a hole. You only need to mark the center. There's a spring-loaded pin in the center that you only need to line up. No need to shift the punch & die set back and forth, to and from, to get your crosshairs to line up with any quartermarks on the die.

Second, you do not need to remove (spin, spin, spin, spin, spin....) the punch from the draw stud as there isn't one. As soon as you release the hydraulic pressure, you're ready for the next punch. This also means you don't need to spin, spin, spin, spin, spin the punch back onto the draw stud to get ready for the next hole.

Third, since there's no draw stud, so you don't need to predrill any holes. As soon as the center is marked, you're making your FINAL KO. You're not drilling a 3/8" hole so you can punch out a 1/2" KO, then swapping the draw stud out so you can punch a 3/4 or 1" KO. YOU'RE DONE!

The OP asked for ways to save time. Here's one way.
 

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you're right but atleast $1500 for that tool.. hard to bite.. i know it's a labor saving device..maybe harbor freight will come with a knock off of that version.

hb, I bought that harbor freight hydraulic punch for $139 before 20% off. It works great, i also own harbor step-bits.
 

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That c-punch i can see being a big time saver as all you need to do is some measuring, slip it in and punch. Wires wont be in the way, no cutting old panels up "time wasted" and no steel filings to clean up. But unless you get a smoking deal or you do enough hole punching to warrant the purchase then the hole saw or manual knockouts are the way to go. For the few holes i punch i use my manual set from greenlee that go up to 2", beyond that i use holesaws. I also try to use existing knockouts for the punch tool so i save on drilling.
 

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That C-punch looks saweeeeet I've only ever seen the hydraulic slugbusters being used, never a c-style. 480, if you ever see another one up for $138 gimme a ring I'l give ya a cool $200!

I use the old-fashion drill pilot hole, pop in the punch and get wrenching...slow but I really don't do that many knockouts.

i also own harbor step-bits.
Are they decent? I've bought cheap-o step bits and it was a big mistake, now I have all Greenlee, Hilti and Lennox all of which I'm very happy with.

Someone makes a stamp that fits in the pipe to mark the panel.
Thats cool!
 
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